The authors conducted a series of multiple regression analyses of data from depressed patients. They found that 8 factors consistently predicted treatment response: a lower initial level of distress, imipramine treatment, a positive attitude toward group psychotherapy, and a good employment history predicted lower posttreatment distress levels; estrogen maintenance treatment was related to better response to diazepam, and a low level of intelligence predicted better response to both diazepam and imipramine; and a low initial level of interpersonal sensitivity and a significant other's having an unfavorable attitude toward psychiatric treatment were associated with better response to group psychotherapy. Multiple regression analyses of experimental data from emotionally depressed patients were conducted to determine factors bearing on the prediction of response to 6 types of treatment of depression. The following 8 factors were found to consistently predict favorable response to treatment: 1) lower initial level of distress, 2) treatment with imipramine, 3) a good employment history, 4) a positive attitude toward group psychotherapy, 5) estrogen replacement therapy enhanced the response to diazepam, 6) a low level of intelligence was predictive of a better response to diazepam and imipramine, 7) a low initial level of interpersonal intersensitivity, and 8) an unfavorable attitude toward psychiatric treatment was associated with a better response to group psychotherapy.